Today we came out for only system not heating Lennox 3.5 ton heat pump single stage with zoning. Cycled equipment from thermostat found no low voltage at heat pump. Upon further evaluation of equipment from failed transformer from power outage last Friday. Client has minimal flood protection, no bypass on zoning and single stage equipment with zoning. Installed new transformer, started system up checked operations and left equipment operational. Will schedule install supervisor to give options on updating.